diff --git a/modules/ve-mw/ui/pages/ve.ui.MWCategoriesPage.js b/modules/ve-mw/ui/pages/ve.ui.MWCategoriesPage.js
index 5478171da5..8d993ffbf3 100644
--- a/modules/ve-mw/ui/pages/ve.ui.MWCategoriesPage.js
+++ b/modules/ve-mw/ui/pages/ve.ui.MWCategoriesPage.js
@@ -257,7 +257,7 @@ ve.ui.MWCategoriesPage.prototype.setup = function ( metaList ) {
 	this.categoryWidget.addItems( this.getCategoryItems() );
 
 	this.defaultSortInput.setValue(
-		defaultSortKeyItem ? defaultSortKeyItem.getAttribute( 'content' ) : ''
+		defaultSortKeyItem ? defaultSortKeyItem.getAttribute( 'content' ) : this.fallbackDefaultSortKey
 	);
 	this.defaultSortKeyTouched = false;
 
@@ -290,7 +290,7 @@ ve.ui.MWCategoriesPage.prototype.teardown = function ( data ) {
 	if ( data && data.action === 'apply' ) {
 		// Alter the default sort key iff it's been touched & is actually different
 		if ( this.defaultSortKeyTouched ) {
-			if ( newDefaultSortKey === '' ) {
+			if ( newDefaultSortKey === '' || newDefaultSortKey === this.fallbackDefaultSortKey ) {
 				if ( currentDefaultSortKeyItem ) {
 					currentDefaultSortKeyItem.remove();
 				}
diff --git a/modules/ve-mw/ui/widgets/ve.ui.MWCategoryPopupWidget.js b/modules/ve-mw/ui/widgets/ve.ui.MWCategoryPopupWidget.js
index 41a01e319b..98276c79c1 100644
--- a/modules/ve-mw/ui/widgets/ve.ui.MWCategoryPopupWidget.js
+++ b/modules/ve-mw/ui/widgets/ve.ui.MWCategoryPopupWidget.js
@@ -27,6 +27,7 @@ ve.ui.MWCategoryPopupWidget = function VeUiMWCategoryPopupWidget( config ) {
 	this.removed = false;
 	this.$title = $( '<label>' );
 	this.$menu = $( '<div>' );
+	this.fallbackSortKey = mw.config.get( 'wgTitle' );
 	this.removeButton = new OO.ui.ButtonWidget( {
 		framed: false,
 		icon: 'trash',
@@ -134,7 +135,11 @@ ve.ui.MWCategoryPopupWidget.prototype.onToggle = function ( show ) {
 	}
 	newSortkey = this.sortKeyInput.$input.val();
 	if ( !this.removed && newSortkey !== ( this.origSortkey || '' ) ) {
-		this.emit( 'updateSortkey', this.category, this.sortKeyInput.$input.val() );
+		if ( newSortkey === this.fallbackSortKey ) {
+			this.emit( 'updateSortkey', this.category, '' );
+		} else {
+			this.emit( 'updateSortkey', this.category, this.sortKeyInput.$input.val() );
+		}
 	}
 };
 
@@ -145,7 +150,7 @@ ve.ui.MWCategoryPopupWidget.prototype.onToggle = function ( show ) {
  * @param {ve.ui.MWCategoryItemWidget} item Category item
  */
 ve.ui.MWCategoryPopupWidget.prototype.loadCategoryIntoPopup = function ( item ) {
-	this.origSortkey = item.sortKey;
+	this.origSortkey = item.sortKey || this.fallbackSortKey;
 	if ( item.isHidden ) {
 		this.$hiddenStatus.text( ve.msg( 'visualeditor-dialog-meta-categories-hidden' ) );
 	} else if ( item.isMissing ) {
@@ -153,7 +158,7 @@ ve.ui.MWCategoryPopupWidget.prototype.loadCategoryIntoPopup = function ( item )
 	} else {
 		this.$hiddenStatus.empty();
 	}
-	this.sortKeyInput.$input.val( item.sortKey );
+	this.sortKeyInput.$input.val( this.origSortkey );
 };
 
 /**
@@ -176,7 +181,7 @@ ve.ui.MWCategoryPopupWidget.prototype.closePopup = function () {
  * @param {string} value Default sort key value
  */
 ve.ui.MWCategoryPopupWidget.prototype.setDefaultSortKey = function ( value ) {
-	this.sortKeyInput.$input.attr( 'placeholder', value );
+	this.fallbackSortKey = value;
 };
 
 /**